Lignumis has a (unhandled) reference to quality modules which causes it to fail to load properly without the Quality mod enabled. Quality is not a listed dependency for Lignumis so I consider this a bug. I think you can fix it with an if exist statement but if not remember that they made Quality optional in 2.1 so if it is required then it should probably be listed in the dependencies to prevent confusion/loading errors.
Come to think of it I didn't even try to load without elevated rails, who ever would?
